Internal-combustion engine



Oct. 27, 1953 E. .1. HouDRY 2,656,830

INTERNAL-COMBUSTION ENGINE Filed Maron 19, 1951 2 sheets-sheet 1 2 l ud-\ ,lfah d FIG.

IN V HV TOR.

EUGEN J Hoz/DRV BY ATTORNEY Oct. 27, 1953 E. J. HOUDRY 2,555,830

INTERNAL COMBUSTION ENGINE Filed March 19, 1951 2 Sheets-Sheet 2 /l l VW l V IN V EN TOR.

EUGENE J HOUD?,V

BY l

ATTQRNvEY Patented Oct. 27, 1953 UNITED STATES PATENT OFFICE 8 Claims.

This invention relates to internal combustion engines and to ways andmeans for improving the operation and the efficiency of the same. Moreparticularly it has to do with the combustion of the motive fuel and tominimizing the importance of the knock rating of fuels, especially ofthose in the gasoline boiling range. In certain respects it may beconsidered as a further development of or improvement on the inventionset forth in my copending U. S. application Serial No. '790,216 filedDecember 6, 1947, now Patent No. 2,552,555.

Among the objects of the invention are to adapt internal combustionengines readily and easily to operate on low octane fuel, to providepractical and relatively inexpensive devices and apparatus for effectingpartial oxidation of fuel by catalytic means thereby to permit the useof low octane fuel without sacrifice of engine efliciency, to permitconvenient adjustment of the catalyst for maximum eiiiciency as well asfor inspection and/or replacement of the catalytic means, and to adaptall engines regardless of age to utilize partial catalytic oxidation offuel at minimum expense for new parts. Other objects will be apparentfrom the detailed description which follows.

In accordance with the invention the oxidizing catalysts for partialoxidation of fuel and for preventing detonation or knocking are mountedon one or more plugs, similar in certain respects to spark plugs andlike the latter arranged to be threaded or otherwise secured in suitableopenings therefore in the engine walls for convenient insertion andremovable Without dismantling any parts of the engine. When such plugsare in place they dispose the oxidation catalysts carried thereby atsuitable locations with reference to the combustion chamber and so as toextend into or to communicate with the latter. The plugs may take avariety of forms but in most instances it is desirable to provide foradjustment of the extent of projection of the catalyst within thecombustion chamber of the engine. By preference the location of theplugs is at or adjacent the periphery of the piston chamber and at oneor more points remote from the locus of spark ignition of each cylinder.Conversion of an engine in most instances involves merely thesubstitution for the old cylinder head of a new head adapted to utilizecatalytic plugs in addition to conventional spark plugs.

In order to illustrate the invention and the manner of its use, concreteembodiments thereof are shown in the accompanying drawings in which:

Fig. l is a top plan view, somewhat diagrammatic, of a six cylinderinternal combustion engine Fig. 2 is a partial transverse sectional viewon an enlarged scale on the broken line 2 2 of Fig. 1;

Fig. 3 is a bottom plan view of the catalytic plug shown in Fig. 2;

Fig. 4 is a bottomplan View of anothercatalytic plug showing a modifiedarrangement of the catalytic elements;

Fig. 5 vis a sectional view on the line 5-5 of Fig. 3;

Figs. 6 and 7 are rcross sectional views at right anglesto each other ofanother modification of the catalytic plug for use in the engine ofFigs. 1 and' 2';

Fig. 8 is a fragmentary top plan view of the internal combustion engineof Fig. 1 showing a different cylinder head having several catalyticplugs for each cylinder, this view being on the scale of Fig, l;

Fig. 9 is a partial transverse sectional view on an enlarged scale online 9 9 of Fig. 8 showing one catalytic plugin sectionand another inelevation; and j .i f

Fig. l0 is a fragmentary sectional view on the line Ill-I0 of Fig. 8 andon a somewhat larger scale than Fig. 9, the parts of the catalytic plugbeing shown in elevation, broken away and in section.

In Figs. 1 and 2 an internal combustion engine is shown having acylinder head II which is provided along one side with a series ofthreaded openings I2, in which are mounted spark plugs a, one spark plugfor eachY cylinder, the spark plugs being connected by ywiring b, to asuitable distributor c, for providing spark ignition to each of thecylinders d of theengine to effect reciprocation of pistons e (Fig. 2).Cylinder head II is also providedl along the other side thereof with aseries of somewhat larger threaded openings I3 above pistons c, one suchopening I3 for each cylinder and substantially on or near the innerperiphery of each cylinder and at a location remote from its spark pluga. As shown in Fig. 2, the threaded portion of opening I3 does notextend entirely through the cylinder head but ends above a narrowannular shoulder I4, while the upper portion of each such opening iscounter-bored at I5 to provide an annular shoulder I6.

Into each of the openings I3 is threaded a catalytic plug II which iscup shaped in form and which may be provided with one or more ridges orribs I8 (Figs. 2 and 5) extending upwardly from the lower closed end ofthe plug to strengthen such portion against the upward thrust from theexplosions of motive fluid in the combustion chamber of each cylinder.The upper inner portion of each plug I1 may be in square or hexagonalform to receive a wrench for screwing the plug into place, and this por-3 tion oi the plug is preferably formed with an outwardly extendingannular ange to be received in counterbore l and to engage a suitablegasket IS seated on shoulder IG. The lower end of plug l1 has acylindrical reduced portion to extend beyond lower shoulder if (Fig. 2)so as to dispose its lower face substantially even with the adjacentwall of the combustion chamber when the catalytic plug is in place. Inor upon this lower face of this reduced portion 20 are mounted suitablecatalysts or catalytic means for oxidizing a portion of the fuel chargedto each cylinder. As shown in Figs. 2, 3 and 5, such catalytic meanstake the form of elongate elements such as strips or slides 2i providedwith laterally enlarged bases received in grooves 22 or correspondingshape in the bottom of each plug l1, such grooves having undercut sidesas shown in order to hold the slides firmly in place. 2l which projectbelow the lower face of each plug l1 are or catalytic material or arecoated with catalyst or will otherwise have suitable oxidizing catalystsmounted thereon. By preference elements or slides 2l are formed ofceramic material, especially of dense compact porcelaneous material ofthe general type used for the cores of spark plugs, which materials havebeen red at high temperatures, as in the range of 2509 to 3900 F., tomake them strong, stable and catalytically inert. To render such slidesactive for the desired oxidation reaction the slides will by preferencefirst be coated with a suitable base i-llin of active alumina (oralternatively of active magnesia, beryllia, or thoria) and then suchbase iilm will be impregnated with a small quantity of any known orsuitable oxidizing catalyst, such as platinum, silver, copper, etc. Suchcatalytic structure and composition is characterized by sustained highactivity and long life.

As shown in Figs. 2, 3 and 5, the strips or slides 2l having catalyticmaterial thereon are three in number, the central strip extending acrossthe center of projection 20 on the plug, while the two side strips 2lalso extend across the bottom of the plug, but in directions divergingfrom the central strip. Fig. A. shows another arrangement in which thesame number of straight strips or slides for supporting oxidizingcatalytic material are provided, but in this instance strips 23a are inparallel and of equal length on opposite sides of the central lineacross the bottom of the plug, and there is a shorter strip 23hextending crosswise or at right angles to strips 23a. In mounting theplugs of the type shown in Figs. 3, 4 and 5, the center strip 2l (or theparallel strips 23a) should extend in general radially of the cylinder,as shown in Fig. 2 or, in other words, should point toward the lowerside of the cylinder head, as Viewed in Fig. l. Grooves or punch marks(not shown) may be made on the top of each plug l1 and on adjacentportions or" the cylinder head, or other suitable means may be utilizedto insure proper positioning of the catalytic strips 2l, or 23a in thecombustion chamber when the plug is screwed home, and gaskets i6 ofdiffering thickness may be utilized to insure each plug l1 being tightlyin place when the strips are properly positioned.

Figs. 6 and '1 show still another form of catalytic plug which may besubstituted for plugs I1 of Figs. 1 to 5. Plug 21 of Figs. 6 and 7 is inthe form of a cylindrical metallic shell threaded internally as well asexternally, as shown, and pro- Those portions of slides H videdinternally with an annular stop shoulder 28. A core 23 of inertporcelaneous material, of .the same general composition as that of thestrips or slides 2| for the rst form of the invention, is shaped to twithin the central bore of shell 21 and to have a reduced portion 29awith catalytic material thereon to extend through the open end of theshell and to provide a shoulder 30 on core 29 opposite stop shoulder 28.Between shoulders 28 and 30 are inserted one or more spacing members orgaskets 3l to provide for adjustment oi" the extent of projection ofreduced portion Za beyond the end of shell 21. Upon the top of core 29is placed an insulating washer 32 of asbestos or other suitablematerial, against which a threaded plug 33 bears to secure core 29 inplace. rhe lower reduced end 21a of shell 21 may have a series of rods34 extending in parallelism across the open end of the shell, such rodsbeing loosely received in grooves therefor in the projecting portion 29aof the catalytic core, so that such projecting portion takes the form ofa series of ridges (Fig. 7). If desired, there may be additional rods(not shown) extending across the open end of shell 21 at right angles torods 34, in which case the lower end of catalytic core 29 will haveadditional cross grooves forming projections such as those on a waiiiegrid. Rods 34 serve to distribute the heat of combustion of the fuel inthe combustion chamber evenly across the plug 29 and also serve assafety means to prevent pieces of the core from falling into thecombustion chamber in the event that the core should become cracked orbroken.

Figs. and 9 show a fragmentary portion of the engine of Fig. 1 butequipped with a cylinder head El providing three threaded openings 43per cylinder for catalytic plugs, in addition to a threaded opening forspark plug a. Openings 43 are of smaller size than threaded opening I3of Figs. 1 and 2, and the catalytic plugs 41 ntting the same are also oismaller size but of the general construction of the form of plug shownin Fig. 6 and Fig. 7. The three plugs 'i1 are arranged around theperiphery of each cylinder as indicated in Fig. 8. Each plug comprisesan annular. shell t1 with an open lower end oi" reduced size. The lowerportion of shell 41 is arranged to engage a suitable gasket 48, restingupon a shoulder '29 provided by cylinder head fil at the lower end ofthe threaded portion of each opening 3. Within the shell 41 is theporcelaneous core 5B which is provided with a reduced lower end 50a forsupporting catalytic material and adapted to project beyond the lowerface of cylinder head 4I when the plug is in place. Gne or more spacinggaskets 5| are mounted between shoulder 52 on core 50 and the opposingshoulder 53 on shell :31, to permit adjustment of the extent ofprojection of core extension 56a into the combustion chamber of theengine. A washer of insulating material 513 rests upon the top of core56, and a threaded plug 55 1s screwed down upon washer 54 to retain core50 in place.

iis shown in Figs. 9 and 10, catalytic plug Il? which is nearest tospark plug a, requires some modication in the contour of the lower wallof cylinder head 4l to permit the fluids in the piston chamber to haveaccess to the lower oi' projecting end of catalytic core 50a as Well asto provide adequate depth in the threaded opening da for the catalyticplug at such location. To this end a portion of the underface ofcylinder head 4| is recessed upwardly, as at 60 (Figs. 9 and 10), whilean adjacent portion 6| is correspondingly extended downwardly to presentan adequate thickness of wall for the shoulder 49 against which thelower end of shell 41 of the catalytic plug seats when such plug is inplace.

In operation the engine of Figs. 1 or 8 will start like a conventionalengine with spark plug ignition and will continue to. operate on sparkplug ignition until the oxidizing catalyst on plugs I1, 21 or 41 becomesheated to operating temperature by the explosions of the motive fluid inthe cylinders. Platinum catalysts come into operation at temperatures ofthe order of 550-600 F. Other oxidizing catalysts such as silver,copper, etc. operate at somewhat higher temperatures, as 800 F. orabove. As soon as the catalytic plugs, or rather the catalyst on thelower ends thereof, such as the strips or slides 2|, 23a, 23h or thecore extensions 29a or 50a, reach operating temperature they begin tooxidize the motive fluid in contact therewith and do so in a continuousmanner, as contrasted with the momentary ignition effected by sparkplugs a. Thus as soon as the motive fluid is drawn into cylinder on thesuction stroke of the piston and comes in contact with the catalyticsurfaces of the catalytic plugsy nameless oxidation takes place andcontinues throughout the compression stroke, up to the moment ofignition by the spark plug and even thereafter on the power stroke, justso long as unoxidized fuel is in contact with the catalytic surfaces.The effect of the nameless oxidation of a portion of the motive fluid isto increase the volume of gases within the compression space of eachcylinder and to raise the temperature of such gases, thus creating muchthe same effect as if the compression ratio were increased by mechanicalrnodication of the engine. Moreover, the higher temperature caused bycatalytic oxidation of a part of the fuel causes faster burning of theremainder'when the latter is finally ignited by the spark plug, alsomore extensive flame propagation takes place toward the cold wall of theengine remote from the spark plug where the catalytic plug or plugs willnormally be placed (see Figs. l and 8). The result is a more powerfulpower stroke due to increased compression and higher operatingtemperature. It is when the flame approaches the cold wall in theconventional engine htat heat and pressure usually combine to break downor crack the residual portions of fuel into knocking components and itis this portion of the fuel which the oxidizing catalysts on thecatalytic plugs are designed and intended to transform by catalyticoxidation, with the result that most of the knocking components in thearea are eliminated. Accordingly by utilizing the present inventionmotor fuels of low octane rating including straight run gasoline can beused in conventional engines, whether old or new, by the simpleexpedient of changing the cylinder head to one such as shown in Fig. 1or Fig. 8, which provides for the oonvenient use of catalytic plugs ofthe type herein disclosed.

One large plug, of the type shofwn in Figs. 2 through 7, may beutilized, located by preference as indicated in Figs. 1 and 2 near thecold wall of the engine, or several smaller plugs of the type shown inFigs. 9 and 10 may be utilized. While five or six small plugs percylinder are a possibility in a properly designed cylinder head, two orthree such plugs as indicated in Figs. 8 and 9 are sufficient. Whenusing active oxidation catalysts such as obtained from the platinumgroup, or silver, or copper, with such catalysts finely dispersed on anactive base such as active alumina, magnesia, beryllia, or thoria, from.04 to .16 square inch (and usually about .03 square inch) of catalystsurface per cubic inch of piston displacement provides the necessarysurface to oxidize catalytically sufficient of the motive fluid and alsothe knocking constituents of broken or cracked hydrocarbon moleculescontained in the air-fuel mixture at the time of flame travel in thecombustion chamber resulting from the spark ignition. For example, givena cylinder having a piston displacement of 50 cubic inches, some 4square inches of catalytic surface is required. This area can beprovided by a single large catalytic plug such as I1 or 21, or by threesmaller catalytic plugs such as 41, each having approximately 1.33`square inches of catalytic surface.

The simplest form of plug is shown in Figs. 2 to 5 inclusive, in whichthe metallic portion is cupshaped and in one piece, and the catalyst isattached thereto by porcelain slides fitting in grooves 22 in theunderface of the one-piece plug. The slides 2| 23a or 23h are intendedto fit tightly within the grooves 22 cut in the shallow cylindricalprojection 20 on the bottom of the plug. By preference the slides arecemented in their grooves to insure their remaining in place, but sincethe grooves are cut in the shallow cylindrical extension 20 whose lowerface is substantially flush or even with the upper surface of thecombustion chamber formed by the cylinder head, it is impossible for theslides to work loose or fall into the combustion chamber. If it is foundnecessary to change the extent of projection of the slides into thecombustion chamber, the plugs must be removed from the cylinder head,the slides forced out of the grooves and new slides of greater depthsubstituted.

In the for-ms of the plug shown in Figs. 6 through 10, change in theextent of projection of the catalyst is effected by changing the numberor thickness of gaskets 3| (Figs. 6 and 7) or gaskets 5| (Figs. 9 andl0). The area of the catalytic surface may be increased by grooves andridges in the porcelain core as indicated in Figs. 6 and 7, or bygrooves at right angles to one another producing projections as in awaffle grid. The large porcelain core such as 29 of the plugs shown inFigs. 6 and 7, or the core 50 of the smaller plugs shown in Figs. 9 and10i, have the advantage of maintaining catalytic surfaces at operatingtemperature for a longer time than the relatively thin strips or slides2|, 23a and 23h of Figs. 2 to 5 inclusive which lose heat rather rapidlyto the one-piece plug I1 of Figs. l throughl 5. The insulating washers32 of Figs. 6 and 7 and 51|A of Figs. 9 and l0, also assist in retainingheat in porcelain cores 29 and 50.

Engines are easily adapted to utilize the catalytic plugs by the simpleexpedient of a new cylinder head. The number and size of the catalyticplug openings may be readily determined from the piston displacement ofthe engine cylinder and since all the catalytic plugs shown herein haveprovision for the adjustment of the extent of projection of thecatalytic surface within the combustion chamber, it requires nothingmore than simple experimentation to adjust the engine to bestperformance. With proper adjustment of the amount and disposition of thecatalytic surfaces, engine performance with low octane fuels can beobtained equaling and in many in- 7 stances exceeding performance withhigher octane fuels when the engine is not equipped with the catalyticplugs. An important advantage of the use of the catalytic plugs is theobtaining of what amounts to an increase in compression ratio by theexpedient of effecting flameless oxidation of a portion of the motiveiiuid and Without structural changes in the engine. Moreover, combustionefficiency is improved and carbon deposits in the combustion chamber aregreatly reduced if not completely eliminated. The catalytic plugs arequickly and easily removed for inspection or cleaning, and renewal orreplacement of the catalytic portions thereof when required is alsoreadily effected in an obvious manner.

While the invention has been herein disclosed in what are now consideredto be preferred forms of apparatus, it is to be understood that theinvention is not restricted to the specific details thereof, but coversall changes, modifications and adaptations Within the scope of theappended claims.

I claim as my invention:

l. In combination with an internal combustion engine of thereciprocating piston type, a cylinder head having auxiliary openingsextending from the exterior of the engine to the combustion chamber ofeach cylinder, a removable plug assembly occupying each of saidauxiliary openings, said plug assembly being adapted to be inserted inand removed from said openings from the exterior of the engine, andlwhen inserted in said openings providing a readily replaceablecatalytic surface exposed within the combustion chamber.

2. In combination with an internal combustion engine of thereciprocating piston type, a cylinder head having auxiliary openingsextending from the exterior of the engine to the combustion chamber ofeach cylinder, a plurality of said openings being provided for eachcylinder, a removable plug assembly occupying each of said auxiliaryopenings, said plug assembly being adapted to be inserted in and removedfrom said openings from the exterior of the engine, and when inserted insaid openings providing a readily replaceable catalytic surface exposedwithin the combustion chamber.

3. In combination with an internal combustion engine of thereciprocating piston type, a cylinder head having auxiliary openingsextending from the exterior of the engine to the combustion chamber ofeach cylinder, a plurality of said openings being provided for eachcylinder, a removable plug assembly occupying each of said auxiliaryopenings, said plug assembly being adapted to be inserted in and removedfrom said openings from the exterior of the engine, and when inserted insaid openings providing a readily replaceable catalytic surface exposedwithin the combustion chamber, the amount of catalytic surface providedby said plugs being adjusted so as to dispose within each cylinder from.04 to .16 square inch of oxidizing catalyst surface per cubic inch ofpiston displacement.

4. In combination with an internal combustion engine of thereciprocating piston type, a cylinder head having auxiliary openingsextending from the exterior of the engine to the combustion chamber ofeach cylinder, a plurality of said openings being provided for eachcylinder, a removable plug assembly occupying each of said auxiliaryopenings, said plug assembly comprising a threaded portion adapted to bethreaded into said openings and a catalytic element releasably carriedby said threaded portion at the lower end thereof, the entire plugassembly being adapted to be inserted in and removed from said openingsfrom the exterior of the engine, and when inserted in said openingsproviding a readily replaceable catalytic surface exposed Within thecombustion chamber.

5. A catalytic element adapted for use with internal combustion enginescomprising a core of catalytically inert ceramic material provided witha stop shoulder to permit said core to be positioned Within and retainedby a retaining sleeve, the lower surface of said ceramic core beingprovided with an adherent nlm of cata-lytically active material which isexposed to the combustion chamber of the engine when said core is inplace in said engine.

6. Auxiliary fuel oxidizing means of the catalytic type for use in aninternal combustion engine, said auxiliary fuel oxidizing meanscornprising a removable plug assembly adapted to be inserted from theexterior of the engine and into a bore extending through the enginecylinder head, said plug assembly including a shouldered plug having aslotted face adapted to be exposed Within the engine combustion chamberwhen the plug assembly is positioned within the bore and an insert slideshaped to fit in and to be retained by the slot, said insert slideproviding a catalyst surface exposed within the combustion chamber.

7. Auxiliary fuel oxidizing means of the catalytic type for use in aninternal combustion engine, said auxiliary fuel oxidizing meanscomprising a removable plug assembly adapted to be inserted from theexterior of the engine and into a bore extending through the enginecylinder head, said plug assembly including a sleeve, a ceramic coreadapted to be mounted in said sleeve and to have a portion extendingthrough said sleeve and into the engine combustion chamber exposing acatalyst surface therein, and a plug adapted to enter said sleeve and toretain the ceramic core therein.

8. Auxiliary fuel oxidizing means of the catalytic type for use in aninternal combustion engine, said auxiliary fuel oxidizing meanscomprising a plug assembly adapted to be inserted from the exterior ofthe engine and into a bore extending through the engine cylinder head,said plug assembly including an internally shouldered sleeve, areplaceable shouldered ceramic core adapted to be mounted in said sleeveand to have a portion extending through said sleeve and into the enginecombustion chamber exposing a catalyst surface therein, shims positionedbetween the shoulder of said ceramic core and the internal shoulder ofsaid sleeve to adjust the degree of extension of the catalyst surfaceinto the combustion chamber, and a plug adapted to enter said sleeve andto retain the ceramic core therein.

EUGENE J. HOUDRY.

References Cited in the iile of this patent UNITED STATES PATENTS NumberName Date 1,564,906 Sokal Dec. 8, 1925 2,520,378 Veit Aug. 29, 19502,552,555 Houdry May 15, 1951

